Irreversible Amide‐Linked Covalent Organic Framework for Selective and Ultrafast Gold Recovery

• Published in: Angewandte Chemie International Edition Vol. 59; no. 40; pp. 17607 - 17613
• Main Authors: Qian, Hai‐Long, Meng, Fan‐Lin, Yang, Cheng‐Xiong, Yan, Xiu‐Ping
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 28.09.2020
• Edition: International ed. in English
• Subjects: Adsorption; Building-block exchange; covalent organic frameworks (COFs); Design; Economic conditions; Exchanging; Functional groups; Gold; gold recovery; Hydrogen bonding; Hydrogen bonds; irreversible linkages; Kinetics; Photoelectron spectroscopy; Photoelectrons; Quantum mechanics; Recovery; Selectivity; Triazine; irreversible linkages; Building-block exchange; gold recovery; covalent organic frameworks (COFs)
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202006535

Design of stable adsorbents for selective gold recovery with large capacity and fast adsorption kinetics is of great challenge, but significant for the economy and the environment. Herein, we show the design and preparation of an irreversible amide‐linked covalent organic framework (COF) JNU‐1 via a building block exchange strategy for efficient recovery of gold. JNU‐1 was synthesized through the exchange of 4,4′‐biphenyldicarboxaldehyde (BA) in mother COF TzBA consisting of 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)trianiline (Tz) and BA with terephthaloyl chloride. The irreversible amide linked JNU‐1 gave good stability, unprecedented fast kinetics, excellent selectivity and outstanding adsorption capacity for gold recovery. X‐ray photoelectron spectroscopy along with thermodynamic study and quantum mechanics calculation reveals that the excellent performance of JNU‐1 for gold recovery results from the formation of hydrogen bonds C(N)−H⋅⋅⋅Cl and coordinate interaction of O and Au. The rational design of irreversible bonds as both inherent linkage and functional groups in COFs is a promising way to prepare stable COFs for diverse applications. Going for gold: A building‐block exchange strategy gave an irreversible amide‐linked covalent organic framework (COF). The irreversible‐amide linked COF gave good stability, unprecedented fast adsorption kinetics, excellent selectivity and outstanding adsorption capacity for gold recovery.